Laundry appliances equipment are commonly provided with internal rotating baskets and arranged concentrically to tanks associated with these by means of suspension members, all being surrounded by a structural enclosure. In the case of washing machine with vertical axis and upper opening further exists a stirrer arranged inside the rotary basket and comprising a rotation axis cooperating with an electric engine.
According to the teachings available in the art, several expedients are known for providing selective coupling between the various parts/components of furniture such washing machines, especially between the rotating basket and the stirrer unit.
Thus, it is known the solution of the JP03493120 document, which talks about a selective coupling between the rotating basket and the stirrer of a washing machine, said coupler basically formed by a pivoting lever around an axis orthogonal to the stirrer rotation axis, and said lever includes a projecting portion in one of its ends, intended to cooperate with a specific receptacle. The solution in this document, however, has a disadvantage with respect to coupler performance. This is because said clutch is actuated by operation of a cam mechanism associated with other mechanical components of the washing machine—namely the rod/lever which defines the coupling between the basket and stirrer depends not only on the washing basket filled with water (or flushing fluid) and, moreover, also requires high production costs due to the additional devices necessary for its proper operation.
In this scenario, we highlight the “floating” couplers which are automatically switched according to the presence or absence of water in the environment in which they are arranged. The use of said “floating” couplers becomes interesting in this type of appliance equipment, since the presence or absence of water is inherent in the phases of the washing cycle.
In this sense, it is possible to mention documents U.S. Pat. No. 5,586,455A, US20130312462, BRPI0605507, U.S. Pat. No. 6,951,121, U.S. Pat. No. 5,651,277, US20140182066, U.S. Pat. No. 6,634,193, KR2003024962, CN202193983, KR2005113452, CN203411812, CN203440675, CN2256898 and CN201151827 that each has its own peculiarity, however—and common way among them—all describe washing machines having floating couplers capable to couple concentric and/or collinear axis, and said formed couplers primarily by tubular moving bodies, similar to gloves or cups which comprise toothed surfaces capable of engaging the corresponding teeth provided on the surfaces of said axles due to the vertical linear displacement (up and down) in accordance with the presence or absence of a rinsing fluid (water) during the phases of the machine cycle (washing and centrifugation, for example), so as to transmit, or not, torque between these axes.
This type of solution shows a drawback, because it demands that the components involved in the coupling (axles and coupler) are all aligned with each other, making it difficult to assemble the equipment and generate manufacturing costs related to machining of teeth and the coupler axis (or the mold to manufacture of it, case made of polymer injection, for example).
In an alternative constructive solution, document BRPI1103238 is recited, which aims to solve the problem of selective coupling between basket and stirrer, specifically during the washing steps and centrifugation in particular. This document, however, has a crucial feature of the present invention and other documents cited herein, which consists in the fact that selective coupling occurs by flotation or not the rotating basket per se, and not an intermediate coupler in relation to the basket and stirrer.
Another solution to that issue is described in document BRPI8806595, which provides an intermediate coupler (called “locking device” in the document text in question) between basket and stirrer. Briefly, the solution described by BRPI8806595 (shown in FIGS. 1.1 and 1.2 appended) refers to a first selective locking device (see reference numeral 130) between the basket and the stirrer which is able to switch its position due to the thrust force/gravity generated when filling/emptying the washing basket, wherein said locking device is a skilled floating body to accommodate and move vertically and inwardly along a path defined by walls and receptacles arranged in the basket bottom and stirrer base.
Moreover, said document also envisages a second locking device (see reference numeral 180) disposed between the basket and the wash tank, with both the locking devices 130, 180 being similar in construction and concept, but operating opposing the response to the level of wash liquid. Such a functional difference is primarily due to the dimensioning of each of the enclosures, as well as the own locking devices 130, 180. Occurs, however, that the locking solution disclosed in this document operates so that when the water fills the tank, the locking devices float and prevent the rotation of the basket with the stirrer, and only lock the rotating basket relative to the fixed tank—which can cause undesirable noises. Further, for the locking by means of cylindrical floats as shown in FIGS. 1.1 and 1.2 appended to operate properly, they must necessarily be arranged aligned, since it must be in a same radial position relative to the rotating shaft of the stirrer—which is also a factor that can cause noise during operation of certain stages of the cycle (mainly spin).
In other words, the first locking device 130, when the basket is fed with water, said locking device 130 floats and unlocks the basket stirrer, but when said basket is emptied, the locking device 130 “falls” and performs the lock. On the other hand, for the second locking device 180, when the tank is fed with water, said locking device 180 floats and lock the tank to the basket, but when said tank is emptied, the locking device 180 “falls” unlocking the basket from the tank. Another of the major disadvantages of said document is its construction technique, once it is necessary at least two floating members in a hole and axis fitting system where the shaft is the float member and the stirrer must have holes. As the hole and axles fitting movement will be promoted by the thrust of the water, it is necessary holes of large diameters in both the stirrer and the basket, which sacrifices efforts resistance of the two components, thus limiting the torque required for washing the clothes.
Thus, it appears that, despite some “floating” couplers, more particularly those disclosed by the above-indicated documents prove, in a way, functional to the present day, it is observed that they all require constructive solutions simple that can offer satisfactory benefits for the selective and automatic coupling between basket and stirrer without its disposal/location is a hindrance to appliance equipment manufacture or design as a whole and in order also to promote a significant reduction in noise that occur during the stirring step of the washing cycles.